1 /*- 2 * Copyright (c) 1982, 1986, 1989, 1991, 1993 3 * The Regents of the University of California. 4 * Copyright (c) 2004-2007 Robert N. M. Watson 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 4. Neither the name of the University nor the names of its contributors 16 * may be used to endorse or promote products derived from this software 17 * without specific prior written permission. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 22 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 29 * SUCH DAMAGE. 30 * 31 * From: @(#)uipc_usrreq.c 8.3 (Berkeley) 1/4/94 32 */ 33 34 /* 35 * UNIX Domain (Local) Sockets 36 * 37 * This is an implementation of UNIX (local) domain sockets. Each socket has 38 * an associated struct unpcb (UNIX protocol control block). Stream sockets 39 * may be connected to 0 or 1 other socket. Datagram sockets may be 40 * connected to 0, 1, or many other sockets. Sockets may be created and 41 * connected in pairs (socketpair(2)), or bound/connected to using the file 42 * system name space. For most purposes, only the receive socket buffer is 43 * used, as sending on one socket delivers directly to the receive socket 44 * buffer of a second socket. 45 * 46 * The implementation is substantially complicated by the fact that 47 * "ancillary data", such as file descriptors or credentials, may be passed 48 * across UNIX domain sockets. The potential for passing UNIX domain sockets 49 * over other UNIX domain sockets requires the implementation of a simple 50 * garbage collector to find and tear down cycles of disconnected sockets. 51 * 52 * TODO: 53 * SEQPACKET, RDM 54 * rethink name space problems 55 * need a proper out-of-band 56 */ 57 58 #include <sys/cdefs.h> 59 __FBSDID("$FreeBSD$"); 60 61 #include "opt_ddb.h" 62 #include "opt_mac.h" 63 64 #include <sys/param.h> 65 #include <sys/domain.h> 66 #include <sys/fcntl.h> 67 #include <sys/malloc.h> /* XXX must be before <sys/file.h> */ 68 #include <sys/eventhandler.h> 69 #include <sys/file.h> 70 #include <sys/filedesc.h> 71 #include <sys/jail.h> 72 #include <sys/kernel.h> 73 #include <sys/lock.h> 74 #include <sys/mbuf.h> 75 #include <sys/mount.h> 76 #include <sys/mutex.h> 77 #include <sys/namei.h> 78 #include <sys/proc.h> 79 #include <sys/protosw.h> 80 #include <sys/resourcevar.h> 81 #include <sys/rwlock.h> 82 #include <sys/socket.h> 83 #include <sys/socketvar.h> 84 #include <sys/signalvar.h> 85 #include <sys/stat.h> 86 #include <sys/sx.h> 87 #include <sys/sysctl.h> 88 #include <sys/systm.h> 89 #include <sys/taskqueue.h> 90 #include <sys/un.h> 91 #include <sys/unpcb.h> 92 #include <sys/vnode.h> 93 94 #ifdef DDB 95 #include <ddb/ddb.h> 96 #endif 97 98 #include <security/mac/mac_framework.h> 99 100 #include <vm/uma.h> 101 102 static uma_zone_t unp_zone; 103 static unp_gen_t unp_gencnt; 104 static u_int unp_count; /* Count of local sockets. */ 105 static ino_t unp_ino; /* Prototype for fake inode numbers. */ 106 static int unp_rights; /* File descriptors in flight. */ 107 static struct unp_head unp_shead; /* List of local stream sockets. */ 108 static struct unp_head unp_dhead; /* List of local datagram sockets. */ 109 110 static const struct sockaddr sun_noname = { sizeof(sun_noname), AF_LOCAL }; 111 112 /* 113 * Garbage collection of cyclic file descriptor/socket references occurs 114 * asynchronously in a taskqueue context in order to avoid recursion and 115 * reentrance in the UNIX domain socket, file descriptor, and socket layer 116 * code. See unp_gc() for a full description. 117 */ 118 static struct task unp_gc_task; 119 120 /* 121 * Both send and receive buffers are allocated PIPSIZ bytes of buffering for 122 * stream sockets, although the total for sender and receiver is actually 123 * only PIPSIZ. 124 * 125 * Datagram sockets really use the sendspace as the maximum datagram size, 126 * and don't really want to reserve the sendspace. Their recvspace should be 127 * large enough for at least one max-size datagram plus address. 128 */ 129 #ifndef PIPSIZ 130 #define PIPSIZ 8192 131 #endif 132 static u_long unpst_sendspace = PIPSIZ; 133 static u_long unpst_recvspace = PIPSIZ; 134 static u_long unpdg_sendspace = 2*1024; /* really max datagram size */ 135 static u_long unpdg_recvspace = 4*1024; 136 137 SYSCTL_NODE(_net, PF_LOCAL, local, CTLFLAG_RW, 0, "Local domain"); 138 SYSCTL_NODE(_net_local, SOCK_STREAM, stream, CTLFLAG_RW, 0, "SOCK_STREAM"); 139 SYSCTL_NODE(_net_local, SOCK_DGRAM, dgram, CTLFLAG_RW, 0, "SOCK_DGRAM"); 140 141 SYSCTL_ULONG(_net_local_stream, OID_AUTO, sendspace, CTLFLAG_RW, 142 &unpst_sendspace, 0, "Default stream send space."); 143 SYSCTL_ULONG(_net_local_stream, OID_AUTO, recvspace, CTLFLAG_RW, 144 &unpst_recvspace, 0, "Default stream receive space."); 145 SYSCTL_ULONG(_net_local_dgram, OID_AUTO, maxdgram, CTLFLAG_RW, 146 &unpdg_sendspace, 0, "Default datagram send space."); 147 SYSCTL_ULONG(_net_local_dgram, OID_AUTO, recvspace, CTLFLAG_RW, 148 &unpdg_recvspace, 0, "Default datagram receive space."); 149 SYSCTL_INT(_net_local, OID_AUTO, inflight, CTLFLAG_RD, &unp_rights, 0, 150 "File descriptors in flight."); 151 152 /*- 153 * Locking and synchronization: 154 * 155 * The global UNIX domain socket rwlock (unp_global_rwlock) protects all 156 * global variables, including the linked lists tracking the set of allocated 157 * UNIX domain sockets. The global rwlock also serves to prevent deadlock 158 * when more than one PCB lock is acquired at a time (i.e., during 159 * connect()). Finally, the global rwlock protects uncounted references from 160 * vnodes to sockets bound to those vnodes: to safely dereference the 161 * v_socket pointer, the global rwlock must be held while a full reference is 162 * acquired. 163 * 164 * UNIX domain sockets each have an unpcb hung off of their so_pcb pointer, 165 * allocated in pru_attach() and freed in pru_detach(). The validity of that 166 * pointer is an invariant, so no lock is required to dereference the so_pcb 167 * pointer if a valid socket reference is held by the caller. In practice, 168 * this is always true during operations performed on a socket. Each unpcb 169 * has a back-pointer to its socket, unp_socket, which will be stable under 170 * the same circumstances. 171 * 172 * This pointer may only be safely dereferenced as long as a valid reference 173 * to the unpcb is held. Typically, this reference will be from the socket, 174 * or from another unpcb when the referring unpcb's lock is held (in order 175 * that the reference not be invalidated during use). For example, to follow 176 * unp->unp_conn->unp_socket, you need unlock the lock on unp, not unp_conn, 177 * as unp_socket remains valid as long as the reference to unp_conn is valid. 178 * 179 * Fields of unpcbss are locked using a per-unpcb lock, unp_mtx. Individual 180 * atomic reads without the lock may be performed "lockless", but more 181 * complex reads and read-modify-writes require the mutex to be held. No 182 * lock order is defined between unpcb locks -- multiple unpcb locks may be 183 * acquired at the same time only when holding the global UNIX domain socket 184 * rwlock exclusively, which prevents deadlocks. 185 * 186 * Blocking with UNIX domain sockets is a tricky issue: unlike most network 187 * protocols, bind() is a non-atomic operation, and connect() requires 188 * potential sleeping in the protocol, due to potentially waiting on local or 189 * distributed file systems. We try to separate "lookup" operations, which 190 * may sleep, and the IPC operations themselves, which typically can occur 191 * with relative atomicity as locks can be held over the entire operation. 192 * 193 * Another tricky issue is simultaneous multi-threaded or multi-process 194 * access to a single UNIX domain socket. These are handled by the flags 195 * UNP_CONNECTING and UNP_BINDING, which prevent concurrent connecting or 196 * binding, both of which involve dropping UNIX domain socket locks in order 197 * to perform namei() and other file system operations. 198 */ 199 static struct rwlock unp_global_rwlock; 200 201 #define UNP_GLOBAL_LOCK_INIT() rw_init(&unp_global_rwlock, \ 202 "unp_global_rwlock") 203 204 #define UNP_GLOBAL_LOCK_ASSERT() rw_assert(&unp_global_rwlock, \ 205 RA_LOCKED) 206 #define UNP_GLOBAL_UNLOCK_ASSERT() rw_assert(&unp_global_rwlock, \ 207 RA_UNLOCKED) 208 209 #define UNP_GLOBAL_WLOCK() rw_wlock(&unp_global_rwlock) 210 #define UNP_GLOBAL_WUNLOCK() rw_wunlock(&unp_global_rwlock) 211 #define UNP_GLOBAL_WLOCK_ASSERT() rw_assert(&unp_global_rwlock, \ 212 RA_WLOCKED) 213 #define UNP_GLOBAL_WOWNED() rw_wowned(&unp_global_rwlock) 214 215 #define UNP_GLOBAL_RLOCK() rw_rlock(&unp_global_rwlock) 216 #define UNP_GLOBAL_RUNLOCK() rw_runlock(&unp_global_rwlock) 217 #define UNP_GLOBAL_RLOCK_ASSERT() rw_assert(&unp_global_rwlock, \ 218 RA_RLOCKED) 219 220 #define UNP_PCB_LOCK_INIT(unp) mtx_init(&(unp)->unp_mtx, \ 221 "unp_mtx", "unp_mtx", \ 222 MTX_DUPOK|MTX_DEF|MTX_RECURSE) 223 #define UNP_PCB_LOCK_DESTROY(unp) mtx_destroy(&(unp)->unp_mtx) 224 #define UNP_PCB_LOCK(unp) mtx_lock(&(unp)->unp_mtx) 225 #define UNP_PCB_UNLOCK(unp) mtx_unlock(&(unp)->unp_mtx) 226 #define UNP_PCB_LOCK_ASSERT(unp) mtx_assert(&(unp)->unp_mtx, MA_OWNED) 227 228 static int unp_connect(struct socket *, struct sockaddr *, 229 struct thread *); 230 static int unp_connect2(struct socket *so, struct socket *so2, int); 231 static void unp_disconnect(struct unpcb *unp, struct unpcb *unp2); 232 static void unp_shutdown(struct unpcb *); 233 static void unp_drop(struct unpcb *, int); 234 static void unp_gc(__unused void *, int); 235 static void unp_scan(struct mbuf *, void (*)(struct file *)); 236 static void unp_discard(struct file *); 237 static void unp_freerights(struct file **, int); 238 static int unp_internalize(struct mbuf **, struct thread *); 239 static void unp_internalize_fp(struct file *); 240 static void unp_externalize_fp(struct file *); 241 static struct mbuf *unp_addsockcred(struct thread *, struct mbuf *); 242 243 /* 244 * Definitions of protocols supported in the LOCAL domain. 245 */ 246 static struct domain localdomain; 247 static struct protosw localsw[] = { 248 { 249 .pr_type = SOCK_STREAM, 250 .pr_domain = &localdomain, 251 .pr_flags = PR_CONNREQUIRED|PR_WANTRCVD|PR_RIGHTS, 252 .pr_ctloutput = &uipc_ctloutput, 253 .pr_usrreqs = &uipc_usrreqs 254 }, 255 { 256 .pr_type = SOCK_DGRAM, 257 .pr_domain = &localdomain, 258 .pr_flags = PR_ATOMIC|PR_ADDR|PR_RIGHTS, 259 .pr_usrreqs = &uipc_usrreqs 260 }, 261 }; 262 263 static struct domain localdomain = { 264 .dom_family = AF_LOCAL, 265 .dom_name = "local", 266 .dom_init = unp_init, 267 .dom_externalize = unp_externalize, 268 .dom_dispose = unp_dispose, 269 .dom_protosw = localsw, 270 .dom_protoswNPROTOSW = &localsw[sizeof(localsw)/sizeof(localsw[0])] 271 }; 272 DOMAIN_SET(local); 273 274 static void 275 uipc_abort(struct socket *so) 276 { 277 struct unpcb *unp, *unp2; 278 279 unp = sotounpcb(so); 280 KASSERT(unp != NULL, ("uipc_abort: unp == NULL")); 281 282 UNP_GLOBAL_WLOCK(); 283 UNP_PCB_LOCK(unp); 284 unp2 = unp->unp_conn; 285 if (unp2 != NULL) { 286 UNP_PCB_LOCK(unp2); 287 unp_drop(unp2, ECONNABORTED); 288 UNP_PCB_UNLOCK(unp2); 289 } 290 UNP_PCB_UNLOCK(unp); 291 UNP_GLOBAL_WUNLOCK(); 292 } 293 294 static int 295 uipc_accept(struct socket *so, struct sockaddr **nam) 296 { 297 struct unpcb *unp, *unp2; 298 const struct sockaddr *sa; 299 300 /* 301 * Pass back name of connected socket, if it was bound and we are 302 * still connected (our peer may have closed already!). 303 */ 304 unp = sotounpcb(so); 305 KASSERT(unp != NULL, ("uipc_accept: unp == NULL")); 306 307 *nam = malloc(sizeof(struct sockaddr_un), M_SONAME, M_WAITOK); 308 UNP_GLOBAL_RLOCK(); 309 unp2 = unp->unp_conn; 310 if (unp2 != NULL && unp2->unp_addr != NULL) { 311 UNP_PCB_LOCK(unp2); 312 sa = (struct sockaddr *) unp2->unp_addr; 313 bcopy(sa, *nam, sa->sa_len); 314 UNP_PCB_UNLOCK(unp2); 315 } else { 316 sa = &sun_noname; 317 bcopy(sa, *nam, sa->sa_len); 318 } 319 UNP_GLOBAL_RUNLOCK(); 320 return (0); 321 } 322 323 static int 324 uipc_attach(struct socket *so, int proto, struct thread *td) 325 { 326 u_long sendspace, recvspace; 327 struct unpcb *unp; 328 int error, locked; 329 330 KASSERT(so->so_pcb == NULL, ("uipc_attach: so_pcb != NULL")); 331 if (so->so_snd.sb_hiwat == 0 || so->so_rcv.sb_hiwat == 0) { 332 switch (so->so_type) { 333 case SOCK_STREAM: 334 sendspace = unpst_sendspace; 335 recvspace = unpst_recvspace; 336 break; 337 338 case SOCK_DGRAM: 339 sendspace = unpdg_sendspace; 340 recvspace = unpdg_recvspace; 341 break; 342 343 default: 344 panic("uipc_attach"); 345 } 346 error = soreserve(so, sendspace, recvspace); 347 if (error) 348 return (error); 349 } 350 unp = uma_zalloc(unp_zone, M_NOWAIT | M_ZERO); 351 if (unp == NULL) 352 return (ENOBUFS); 353 LIST_INIT(&unp->unp_refs); 354 UNP_PCB_LOCK_INIT(unp); 355 unp->unp_socket = so; 356 so->so_pcb = unp; 357 unp->unp_refcount = 1; 358 359 /* 360 * uipc_attach() may be called indirectly from within the UNIX domain 361 * socket code via sonewconn() in unp_connect(). Since rwlocks can 362 * not be recursed, we do the closest thing. 363 */ 364 locked = 0; 365 if (!UNP_GLOBAL_WOWNED()) { 366 UNP_GLOBAL_WLOCK(); 367 locked = 1; 368 } 369 unp->unp_gencnt = ++unp_gencnt; 370 unp_count++; 371 LIST_INSERT_HEAD(so->so_type == SOCK_DGRAM ? &unp_dhead : &unp_shead, 372 unp, unp_link); 373 if (locked) 374 UNP_GLOBAL_WUNLOCK(); 375 376 return (0); 377 } 378 379 static int 380 uipc_bind(struct socket *so, struct sockaddr *nam, struct thread *td) 381 { 382 struct sockaddr_un *soun = (struct sockaddr_un *)nam; 383 struct vattr vattr; 384 int error, namelen, vfslocked; 385 struct nameidata nd; 386 struct unpcb *unp; 387 struct vnode *vp; 388 struct mount *mp; 389 char *buf; 390 391 unp = sotounpcb(so); 392 KASSERT(unp != NULL, ("uipc_bind: unp == NULL")); 393 394 namelen = soun->sun_len - offsetof(struct sockaddr_un, sun_path); 395 if (namelen <= 0) 396 return (EINVAL); 397 398 /* 399 * We don't allow simultaneous bind() calls on a single UNIX domain 400 * socket, so flag in-progress operations, and return an error if an 401 * operation is already in progress. 402 * 403 * Historically, we have not allowed a socket to be rebound, so this 404 * also returns an error. Not allowing re-binding simplifies the 405 * implementation and avoids a great many possible failure modes. 406 */ 407 UNP_PCB_LOCK(unp); 408 if (unp->unp_vnode != NULL) { 409 UNP_PCB_UNLOCK(unp); 410 return (EINVAL); 411 } 412 if (unp->unp_flags & UNP_BINDING) { 413 UNP_PCB_UNLOCK(unp); 414 return (EALREADY); 415 } 416 unp->unp_flags |= UNP_BINDING; 417 UNP_PCB_UNLOCK(unp); 418 419 buf = malloc(namelen + 1, M_TEMP, M_WAITOK); 420 bcopy(soun->sun_path, buf, namelen); 421 buf[namelen] = 0; 422 423 restart: 424 vfslocked = 0; 425 NDINIT(&nd, CREATE, MPSAFE | NOFOLLOW | LOCKPARENT | SAVENAME, 426 UIO_SYSSPACE, buf, td); 427 /* SHOULD BE ABLE TO ADOPT EXISTING AND wakeup() ALA FIFO's */ 428 error = namei(&nd); 429 if (error) 430 goto error; 431 vp = nd.ni_vp; 432 vfslocked = NDHASGIANT(&nd); 433 if (vp != NULL || vn_start_write(nd.ni_dvp, &mp, V_NOWAIT) != 0) { 434 NDFREE(&nd, NDF_ONLY_PNBUF); 435 if (nd.ni_dvp == vp) 436 vrele(nd.ni_dvp); 437 else 438 vput(nd.ni_dvp); 439 if (vp != NULL) { 440 vrele(vp); 441 error = EADDRINUSE; 442 goto error; 443 } 444 error = vn_start_write(NULL, &mp, V_XSLEEP | PCATCH); 445 if (error) 446 goto error; 447 VFS_UNLOCK_GIANT(vfslocked); 448 goto restart; 449 } 450 VATTR_NULL(&vattr); 451 vattr.va_type = VSOCK; 452 vattr.va_mode = (ACCESSPERMS & ~td->td_proc->p_fd->fd_cmask); 453 #ifdef MAC 454 error = mac_vnode_check_create(td->td_ucred, nd.ni_dvp, &nd.ni_cnd, 455 &vattr); 456 #endif 457 if (error == 0) { 458 VOP_LEASE(nd.ni_dvp, td, td->td_ucred, LEASE_WRITE); 459 error = VOP_CREATE(nd.ni_dvp, &nd.ni_vp, &nd.ni_cnd, &vattr); 460 } 461 NDFREE(&nd, NDF_ONLY_PNBUF); 462 vput(nd.ni_dvp); 463 if (error) { 464 vn_finished_write(mp); 465 goto error; 466 } 467 vp = nd.ni_vp; 468 ASSERT_VOP_ELOCKED(vp, "uipc_bind"); 469 soun = (struct sockaddr_un *)sodupsockaddr(nam, M_WAITOK); 470 471 UNP_GLOBAL_WLOCK(); 472 UNP_PCB_LOCK(unp); 473 vp->v_socket = unp->unp_socket; 474 unp->unp_vnode = vp; 475 unp->unp_addr = soun; 476 unp->unp_flags &= ~UNP_BINDING; 477 UNP_PCB_UNLOCK(unp); 478 UNP_GLOBAL_WUNLOCK(); 479 VOP_UNLOCK(vp, 0); 480 vn_finished_write(mp); 481 VFS_UNLOCK_GIANT(vfslocked); 482 free(buf, M_TEMP); 483 return (0); 484 485 error: 486 VFS_UNLOCK_GIANT(vfslocked); 487 UNP_PCB_LOCK(unp); 488 unp->unp_flags &= ~UNP_BINDING; 489 UNP_PCB_UNLOCK(unp); 490 free(buf, M_TEMP); 491 return (error); 492 } 493 494 static int 495 uipc_connect(struct socket *so, struct sockaddr *nam, struct thread *td) 496 { 497 int error; 498 499 KASSERT(td == curthread, ("uipc_connect: td != curthread")); 500 UNP_GLOBAL_WLOCK(); 501 error = unp_connect(so, nam, td); 502 UNP_GLOBAL_WUNLOCK(); 503 return (error); 504 } 505 506 static void 507 uipc_close(struct socket *so) 508 { 509 struct unpcb *unp, *unp2; 510 511 unp = sotounpcb(so); 512 KASSERT(unp != NULL, ("uipc_close: unp == NULL")); 513 514 UNP_GLOBAL_WLOCK(); 515 UNP_PCB_LOCK(unp); 516 unp2 = unp->unp_conn; 517 if (unp2 != NULL) { 518 UNP_PCB_LOCK(unp2); 519 unp_disconnect(unp, unp2); 520 UNP_PCB_UNLOCK(unp2); 521 } 522 UNP_PCB_UNLOCK(unp); 523 UNP_GLOBAL_WUNLOCK(); 524 } 525 526 int 527 uipc_connect2(struct socket *so1, struct socket *so2) 528 { 529 struct unpcb *unp, *unp2; 530 int error; 531 532 UNP_GLOBAL_WLOCK(); 533 unp = so1->so_pcb; 534 KASSERT(unp != NULL, ("uipc_connect2: unp == NULL")); 535 UNP_PCB_LOCK(unp); 536 unp2 = so2->so_pcb; 537 KASSERT(unp2 != NULL, ("uipc_connect2: unp2 == NULL")); 538 UNP_PCB_LOCK(unp2); 539 error = unp_connect2(so1, so2, PRU_CONNECT2); 540 UNP_PCB_UNLOCK(unp2); 541 UNP_PCB_UNLOCK(unp); 542 UNP_GLOBAL_WUNLOCK(); 543 return (error); 544 } 545 546 /* control is EOPNOTSUPP */ 547 548 static void 549 uipc_detach(struct socket *so) 550 { 551 struct unpcb *unp, *unp2; 552 struct sockaddr_un *saved_unp_addr; 553 struct vnode *vp; 554 int freeunp, local_unp_rights; 555 556 unp = sotounpcb(so); 557 KASSERT(unp != NULL, ("uipc_detach: unp == NULL")); 558 559 UNP_GLOBAL_WLOCK(); 560 UNP_PCB_LOCK(unp); 561 562 LIST_REMOVE(unp, unp_link); 563 unp->unp_gencnt = ++unp_gencnt; 564 --unp_count; 565 566 /* 567 * XXXRW: Should assert vp->v_socket == so. 568 */ 569 if ((vp = unp->unp_vnode) != NULL) { 570 unp->unp_vnode->v_socket = NULL; 571 unp->unp_vnode = NULL; 572 } 573 unp2 = unp->unp_conn; 574 if (unp2 != NULL) { 575 UNP_PCB_LOCK(unp2); 576 unp_disconnect(unp, unp2); 577 UNP_PCB_UNLOCK(unp2); 578 } 579 580 /* 581 * We hold the global lock, so it's OK to acquire multiple pcb locks 582 * at a time. 583 */ 584 while (!LIST_EMPTY(&unp->unp_refs)) { 585 struct unpcb *ref = LIST_FIRST(&unp->unp_refs); 586 587 UNP_PCB_LOCK(ref); 588 unp_drop(ref, ECONNRESET); 589 UNP_PCB_UNLOCK(ref); 590 } 591 local_unp_rights = unp_rights; 592 UNP_GLOBAL_WUNLOCK(); 593 unp->unp_socket->so_pcb = NULL; 594 saved_unp_addr = unp->unp_addr; 595 unp->unp_addr = NULL; 596 unp->unp_refcount--; 597 freeunp = (unp->unp_refcount == 0); 598 if (saved_unp_addr != NULL) 599 FREE(saved_unp_addr, M_SONAME); 600 if (freeunp) { 601 UNP_PCB_LOCK_DESTROY(unp); 602 uma_zfree(unp_zone, unp); 603 } else 604 UNP_PCB_UNLOCK(unp); 605 if (vp) { 606 int vfslocked; 607 608 vfslocked = VFS_LOCK_GIANT(vp->v_mount); 609 vrele(vp); 610 VFS_UNLOCK_GIANT(vfslocked); 611 } 612 if (local_unp_rights) 613 taskqueue_enqueue(taskqueue_thread, &unp_gc_task); 614 } 615 616 static int 617 uipc_disconnect(struct socket *so) 618 { 619 struct unpcb *unp, *unp2; 620 621 unp = sotounpcb(so); 622 KASSERT(unp != NULL, ("uipc_disconnect: unp == NULL")); 623 624 UNP_GLOBAL_WLOCK(); 625 UNP_PCB_LOCK(unp); 626 unp2 = unp->unp_conn; 627 if (unp2 != NULL) { 628 UNP_PCB_LOCK(unp2); 629 unp_disconnect(unp, unp2); 630 UNP_PCB_UNLOCK(unp2); 631 } 632 UNP_PCB_UNLOCK(unp); 633 UNP_GLOBAL_WUNLOCK(); 634 return (0); 635 } 636 637 static int 638 uipc_listen(struct socket *so, int backlog, struct thread *td) 639 { 640 struct unpcb *unp; 641 int error; 642 643 unp = sotounpcb(so); 644 KASSERT(unp != NULL, ("uipc_listen: unp == NULL")); 645 646 UNP_PCB_LOCK(unp); 647 if (unp->unp_vnode == NULL) { 648 UNP_PCB_UNLOCK(unp); 649 return (EINVAL); 650 } 651 652 SOCK_LOCK(so); 653 error = solisten_proto_check(so); 654 if (error == 0) { 655 cru2x(td->td_ucred, &unp->unp_peercred); 656 unp->unp_flags |= UNP_HAVEPCCACHED; 657 solisten_proto(so, backlog); 658 } 659 SOCK_UNLOCK(so); 660 UNP_PCB_UNLOCK(unp); 661 return (error); 662 } 663 664 static int 665 uipc_peeraddr(struct socket *so, struct sockaddr **nam) 666 { 667 struct unpcb *unp, *unp2; 668 const struct sockaddr *sa; 669 670 unp = sotounpcb(so); 671 KASSERT(unp != NULL, ("uipc_peeraddr: unp == NULL")); 672 673 *nam = malloc(sizeof(struct sockaddr_un), M_SONAME, M_WAITOK); 674 UNP_PCB_LOCK(unp); 675 /* 676 * XXX: It seems that this test always fails even when connection is 677 * established. So, this else clause is added as workaround to 678 * return PF_LOCAL sockaddr. 679 */ 680 unp2 = unp->unp_conn; 681 if (unp2 != NULL) { 682 UNP_PCB_LOCK(unp2); 683 if (unp2->unp_addr != NULL) 684 sa = (struct sockaddr *) unp->unp_conn->unp_addr; 685 else 686 sa = &sun_noname; 687 bcopy(sa, *nam, sa->sa_len); 688 UNP_PCB_UNLOCK(unp2); 689 } else { 690 sa = &sun_noname; 691 bcopy(sa, *nam, sa->sa_len); 692 } 693 UNP_PCB_UNLOCK(unp); 694 return (0); 695 } 696 697 static int 698 uipc_rcvd(struct socket *so, int flags) 699 { 700 struct unpcb *unp, *unp2; 701 struct socket *so2; 702 u_int mbcnt, sbcc; 703 u_long newhiwat; 704 705 unp = sotounpcb(so); 706 KASSERT(unp != NULL, ("uipc_rcvd: unp == NULL")); 707 708 if (so->so_type == SOCK_DGRAM) 709 panic("uipc_rcvd DGRAM?"); 710 711 if (so->so_type != SOCK_STREAM) 712 panic("uipc_rcvd unknown socktype"); 713 714 /* 715 * Adjust backpressure on sender and wakeup any waiting to write. 716 * 717 * The unp lock is acquired to maintain the validity of the unp_conn 718 * pointer; no lock on unp2 is required as unp2->unp_socket will be 719 * static as long as we don't permit unp2 to disconnect from unp, 720 * which is prevented by the lock on unp. We cache values from 721 * so_rcv to avoid holding the so_rcv lock over the entire 722 * transaction on the remote so_snd. 723 */ 724 SOCKBUF_LOCK(&so->so_rcv); 725 mbcnt = so->so_rcv.sb_mbcnt; 726 sbcc = so->so_rcv.sb_cc; 727 SOCKBUF_UNLOCK(&so->so_rcv); 728 UNP_PCB_LOCK(unp); 729 unp2 = unp->unp_conn; 730 if (unp2 == NULL) { 731 UNP_PCB_UNLOCK(unp); 732 return (0); 733 } 734 so2 = unp2->unp_socket; 735 SOCKBUF_LOCK(&so2->so_snd); 736 so2->so_snd.sb_mbmax += unp->unp_mbcnt - mbcnt; 737 newhiwat = so2->so_snd.sb_hiwat + unp->unp_cc - sbcc; 738 (void)chgsbsize(so2->so_cred->cr_uidinfo, &so2->so_snd.sb_hiwat, 739 newhiwat, RLIM_INFINITY); 740 sowwakeup_locked(so2); 741 unp->unp_mbcnt = mbcnt; 742 unp->unp_cc = sbcc; 743 UNP_PCB_UNLOCK(unp); 744 return (0); 745 } 746 747 /* pru_rcvoob is EOPNOTSUPP */ 748 749 static int 750 uipc_send(struct socket *so, int flags, struct mbuf *m, struct sockaddr *nam, 751 struct mbuf *control, struct thread *td) 752 { 753 struct unpcb *unp, *unp2; 754 struct socket *so2; 755 u_int mbcnt, sbcc; 756 u_long newhiwat; 757 int error = 0; 758 759 unp = sotounpcb(so); 760 KASSERT(unp != NULL, ("uipc_send: unp == NULL")); 761 762 if (flags & PRUS_OOB) { 763 error = EOPNOTSUPP; 764 goto release; 765 } 766 767 if (control != NULL && (error = unp_internalize(&control, td))) 768 goto release; 769 770 if ((nam != NULL) || (flags & PRUS_EOF)) 771 UNP_GLOBAL_WLOCK(); 772 else 773 UNP_GLOBAL_RLOCK(); 774 775 switch (so->so_type) { 776 case SOCK_DGRAM: 777 { 778 const struct sockaddr *from; 779 780 unp2 = unp->unp_conn; 781 if (nam != NULL) { 782 UNP_GLOBAL_WLOCK_ASSERT(); 783 if (unp2 != NULL) { 784 error = EISCONN; 785 break; 786 } 787 error = unp_connect(so, nam, td); 788 if (error) 789 break; 790 unp2 = unp->unp_conn; 791 } 792 /* 793 * Because connect() and send() are non-atomic in a sendto() 794 * with a target address, it's possible that the socket will 795 * have disconnected before the send() can run. In that case 796 * return the slightly counter-intuitive but otherwise 797 * correct error that the socket is not connected. 798 */ 799 if (unp2 == NULL) { 800 error = ENOTCONN; 801 break; 802 } 803 /* Lockless read. */ 804 if (unp2->unp_flags & UNP_WANTCRED) 805 control = unp_addsockcred(td, control); 806 UNP_PCB_LOCK(unp); 807 if (unp->unp_addr != NULL) 808 from = (struct sockaddr *)unp->unp_addr; 809 else 810 from = &sun_noname; 811 so2 = unp2->unp_socket; 812 SOCKBUF_LOCK(&so2->so_rcv); 813 if (sbappendaddr_locked(&so2->so_rcv, from, m, control)) { 814 sorwakeup_locked(so2); 815 m = NULL; 816 control = NULL; 817 } else { 818 SOCKBUF_UNLOCK(&so2->so_rcv); 819 error = ENOBUFS; 820 } 821 if (nam != NULL) { 822 UNP_GLOBAL_WLOCK_ASSERT(); 823 UNP_PCB_LOCK(unp2); 824 unp_disconnect(unp, unp2); 825 UNP_PCB_UNLOCK(unp2); 826 } 827 UNP_PCB_UNLOCK(unp); 828 break; 829 } 830 831 case SOCK_STREAM: 832 /* 833 * Connect if not connected yet. 834 * 835 * Note: A better implementation would complain if not equal 836 * to the peer's address. 837 */ 838 if ((so->so_state & SS_ISCONNECTED) == 0) { 839 if (nam != NULL) { 840 UNP_GLOBAL_WLOCK_ASSERT(); 841 error = unp_connect(so, nam, td); 842 if (error) 843 break; /* XXX */ 844 } else { 845 error = ENOTCONN; 846 break; 847 } 848 } 849 850 /* Lockless read. */ 851 if (so->so_snd.sb_state & SBS_CANTSENDMORE) { 852 error = EPIPE; 853 break; 854 } 855 /* 856 * Because connect() and send() are non-atomic in a sendto() 857 * with a target address, it's possible that the socket will 858 * have disconnected before the send() can run. In that case 859 * return the slightly counter-intuitive but otherwise 860 * correct error that the socket is not connected. 861 * 862 * Locking here must be done carefully: the global lock 863 * prevents interconnections between unpcbs from changing, so 864 * we can traverse from unp to unp2 without acquiring unp's 865 * lock. Socket buffer locks follow unpcb locks, so we can 866 * acquire both remote and lock socket buffer locks. 867 */ 868 unp2 = unp->unp_conn; 869 if (unp2 == NULL) { 870 error = ENOTCONN; 871 break; 872 } 873 so2 = unp2->unp_socket; 874 UNP_PCB_LOCK(unp2); 875 SOCKBUF_LOCK(&so2->so_rcv); 876 if (unp2->unp_flags & UNP_WANTCRED) { 877 /* 878 * Credentials are passed only once on SOCK_STREAM. 879 */ 880 unp2->unp_flags &= ~UNP_WANTCRED; 881 control = unp_addsockcred(td, control); 882 } 883 /* 884 * Send to paired receive port, and then reduce send buffer 885 * hiwater marks to maintain backpressure. Wake up readers. 886 */ 887 if (control != NULL) { 888 if (sbappendcontrol_locked(&so2->so_rcv, m, control)) 889 control = NULL; 890 } else 891 sbappend_locked(&so2->so_rcv, m); 892 mbcnt = so2->so_rcv.sb_mbcnt - unp2->unp_mbcnt; 893 unp2->unp_mbcnt = so2->so_rcv.sb_mbcnt; 894 sbcc = so2->so_rcv.sb_cc; 895 sorwakeup_locked(so2); 896 897 SOCKBUF_LOCK(&so->so_snd); 898 newhiwat = so->so_snd.sb_hiwat - (sbcc - unp2->unp_cc); 899 (void)chgsbsize(so->so_cred->cr_uidinfo, &so->so_snd.sb_hiwat, 900 newhiwat, RLIM_INFINITY); 901 so->so_snd.sb_mbmax -= mbcnt; 902 SOCKBUF_UNLOCK(&so->so_snd); 903 unp2->unp_cc = sbcc; 904 UNP_PCB_UNLOCK(unp2); 905 m = NULL; 906 break; 907 908 default: 909 panic("uipc_send unknown socktype"); 910 } 911 912 /* 913 * SEND_EOF is equivalent to a SEND followed by a SHUTDOWN. 914 */ 915 if (flags & PRUS_EOF) { 916 UNP_PCB_LOCK(unp); 917 socantsendmore(so); 918 unp_shutdown(unp); 919 UNP_PCB_UNLOCK(unp); 920 } 921 922 if ((nam != NULL) || (flags & PRUS_EOF)) 923 UNP_GLOBAL_WUNLOCK(); 924 else 925 UNP_GLOBAL_RUNLOCK(); 926 927 if (control != NULL && error != 0) 928 unp_dispose(control); 929 930 release: 931 if (control != NULL) 932 m_freem(control); 933 if (m != NULL) 934 m_freem(m); 935 return (error); 936 } 937 938 static int 939 uipc_sense(struct socket *so, struct stat *sb) 940 { 941 struct unpcb *unp, *unp2; 942 struct socket *so2; 943 944 unp = sotounpcb(so); 945 KASSERT(unp != NULL, ("uipc_sense: unp == NULL")); 946 947 sb->st_blksize = so->so_snd.sb_hiwat; 948 UNP_GLOBAL_RLOCK(); 949 UNP_PCB_LOCK(unp); 950 unp2 = unp->unp_conn; 951 if (so->so_type == SOCK_STREAM && unp2 != NULL) { 952 so2 = unp2->unp_socket; 953 sb->st_blksize += so2->so_rcv.sb_cc; 954 } 955 sb->st_dev = NODEV; 956 if (unp->unp_ino == 0) 957 unp->unp_ino = (++unp_ino == 0) ? ++unp_ino : unp_ino; 958 sb->st_ino = unp->unp_ino; 959 UNP_PCB_UNLOCK(unp); 960 UNP_GLOBAL_RUNLOCK(); 961 return (0); 962 } 963 964 static int 965 uipc_shutdown(struct socket *so) 966 { 967 struct unpcb *unp; 968 969 unp = sotounpcb(so); 970 KASSERT(unp != NULL, ("uipc_shutdown: unp == NULL")); 971 972 UNP_GLOBAL_WLOCK(); 973 UNP_PCB_LOCK(unp); 974 socantsendmore(so); 975 unp_shutdown(unp); 976 UNP_PCB_UNLOCK(unp); 977 UNP_GLOBAL_WUNLOCK(); 978 return (0); 979 } 980 981 static int 982 uipc_sockaddr(struct socket *so, struct sockaddr **nam) 983 { 984 struct unpcb *unp; 985 const struct sockaddr *sa; 986 987 unp = sotounpcb(so); 988 KASSERT(unp != NULL, ("uipc_sockaddr: unp == NULL")); 989 990 *nam = malloc(sizeof(struct sockaddr_un), M_SONAME, M_WAITOK); 991 UNP_PCB_LOCK(unp); 992 if (unp->unp_addr != NULL) 993 sa = (struct sockaddr *) unp->unp_addr; 994 else 995 sa = &sun_noname; 996 bcopy(sa, *nam, sa->sa_len); 997 UNP_PCB_UNLOCK(unp); 998 return (0); 999 } 1000 1001 struct pr_usrreqs uipc_usrreqs = { 1002 .pru_abort = uipc_abort, 1003 .pru_accept = uipc_accept, 1004 .pru_attach = uipc_attach, 1005 .pru_bind = uipc_bind, 1006 .pru_connect = uipc_connect, 1007 .pru_connect2 = uipc_connect2, 1008 .pru_detach = uipc_detach, 1009 .pru_disconnect = uipc_disconnect, 1010 .pru_listen = uipc_listen, 1011 .pru_peeraddr = uipc_peeraddr, 1012 .pru_rcvd = uipc_rcvd, 1013 .pru_send = uipc_send, 1014 .pru_sense = uipc_sense, 1015 .pru_shutdown = uipc_shutdown, 1016 .pru_sockaddr = uipc_sockaddr, 1017 .pru_close = uipc_close, 1018 }; 1019 1020 int 1021 uipc_ctloutput(struct socket *so, struct sockopt *sopt) 1022 { 1023 struct unpcb *unp; 1024 struct xucred xu; 1025 int error, optval; 1026 1027 if (sopt->sopt_level != 0) 1028 return (EINVAL); 1029 1030 unp = sotounpcb(so); 1031 KASSERT(unp != NULL, ("uipc_ctloutput: unp == NULL")); 1032 error = 0; 1033 switch (sopt->sopt_dir) { 1034 case SOPT_GET: 1035 switch (sopt->sopt_name) { 1036 case LOCAL_PEERCRED: 1037 UNP_PCB_LOCK(unp); 1038 if (unp->unp_flags & UNP_HAVEPC) 1039 xu = unp->unp_peercred; 1040 else { 1041 if (so->so_type == SOCK_STREAM) 1042 error = ENOTCONN; 1043 else 1044 error = EINVAL; 1045 } 1046 UNP_PCB_UNLOCK(unp); 1047 if (error == 0) 1048 error = sooptcopyout(sopt, &xu, sizeof(xu)); 1049 break; 1050 1051 case LOCAL_CREDS: 1052 /* Unlocked read. */ 1053 optval = unp->unp_flags & UNP_WANTCRED ? 1 : 0; 1054 error = sooptcopyout(sopt, &optval, sizeof(optval)); 1055 break; 1056 1057 case LOCAL_CONNWAIT: 1058 /* Unlocked read. */ 1059 optval = unp->unp_flags & UNP_CONNWAIT ? 1 : 0; 1060 error = sooptcopyout(sopt, &optval, sizeof(optval)); 1061 break; 1062 1063 default: 1064 error = EOPNOTSUPP; 1065 break; 1066 } 1067 break; 1068 1069 case SOPT_SET: 1070 switch (sopt->sopt_name) { 1071 case LOCAL_CREDS: 1072 case LOCAL_CONNWAIT: 1073 error = sooptcopyin(sopt, &optval, sizeof(optval), 1074 sizeof(optval)); 1075 if (error) 1076 break; 1077 1078 #define OPTSET(bit) do { \ 1079 UNP_PCB_LOCK(unp); \ 1080 if (optval) \ 1081 unp->unp_flags |= bit; \ 1082 else \ 1083 unp->unp_flags &= ~bit; \ 1084 UNP_PCB_UNLOCK(unp); \ 1085 } while (0) 1086 1087 switch (sopt->sopt_name) { 1088 case LOCAL_CREDS: 1089 OPTSET(UNP_WANTCRED); 1090 break; 1091 1092 case LOCAL_CONNWAIT: 1093 OPTSET(UNP_CONNWAIT); 1094 break; 1095 1096 default: 1097 break; 1098 } 1099 break; 1100 #undef OPTSET 1101 default: 1102 error = ENOPROTOOPT; 1103 break; 1104 } 1105 break; 1106 1107 default: 1108 error = EOPNOTSUPP; 1109 break; 1110 } 1111 return (error); 1112 } 1113 1114 static int 1115 unp_connect(struct socket *so, struct sockaddr *nam, struct thread *td) 1116 { 1117 struct sockaddr_un *soun = (struct sockaddr_un *)nam; 1118 struct vnode *vp; 1119 struct socket *so2, *so3; 1120 struct unpcb *unp, *unp2, *unp3; 1121 int error, len, vfslocked; 1122 struct nameidata nd; 1123 char buf[SOCK_MAXADDRLEN]; 1124 struct sockaddr *sa; 1125 1126 UNP_GLOBAL_WLOCK_ASSERT(); 1127 1128 unp = sotounpcb(so); 1129 KASSERT(unp != NULL, ("unp_connect: unp == NULL")); 1130 1131 len = nam->sa_len - offsetof(struct sockaddr_un, sun_path); 1132 if (len <= 0) 1133 return (EINVAL); 1134 bcopy(soun->sun_path, buf, len); 1135 buf[len] = 0; 1136 1137 UNP_PCB_LOCK(unp); 1138 if (unp->unp_flags & UNP_CONNECTING) { 1139 UNP_PCB_UNLOCK(unp); 1140 return (EALREADY); 1141 } 1142 UNP_GLOBAL_WUNLOCK(); 1143 unp->unp_flags |= UNP_CONNECTING; 1144 UNP_PCB_UNLOCK(unp); 1145 1146 sa = malloc(sizeof(struct sockaddr_un), M_SONAME, M_WAITOK); 1147 NDINIT(&nd, LOOKUP, MPSAFE | FOLLOW | LOCKLEAF, UIO_SYSSPACE, buf, 1148 td); 1149 error = namei(&nd); 1150 if (error) 1151 vp = NULL; 1152 else 1153 vp = nd.ni_vp; 1154 ASSERT_VOP_LOCKED(vp, "unp_connect"); 1155 vfslocked = NDHASGIANT(&nd); 1156 NDFREE(&nd, NDF_ONLY_PNBUF); 1157 if (error) 1158 goto bad; 1159 1160 if (vp->v_type != VSOCK) { 1161 error = ENOTSOCK; 1162 goto bad; 1163 } 1164 #ifdef MAC 1165 error = mac_vnode_check_open(td->td_ucred, vp, VWRITE | VREAD); 1166 if (error) 1167 goto bad; 1168 #endif 1169 error = VOP_ACCESS(vp, VWRITE, td->td_ucred, td); 1170 if (error) 1171 goto bad; 1172 VFS_UNLOCK_GIANT(vfslocked); 1173 1174 unp = sotounpcb(so); 1175 KASSERT(unp != NULL, ("unp_connect: unp == NULL")); 1176 1177 /* 1178 * Lock global lock for two reasons: make sure v_socket is stable, 1179 * and to protect simultaneous locking of multiple pcbs. 1180 */ 1181 UNP_GLOBAL_WLOCK(); 1182 so2 = vp->v_socket; 1183 if (so2 == NULL) { 1184 error = ECONNREFUSED; 1185 goto bad2; 1186 } 1187 if (so->so_type != so2->so_type) { 1188 error = EPROTOTYPE; 1189 goto bad2; 1190 } 1191 if (so->so_proto->pr_flags & PR_CONNREQUIRED) { 1192 if (so2->so_options & SO_ACCEPTCONN) { 1193 /* 1194 * We can't drop the global lock here or 'so2' may 1195 * become invalid. As a result, we need to handle 1196 * possibly lock recursion in uipc_attach. 1197 */ 1198 so3 = sonewconn(so2, 0); 1199 } else 1200 so3 = NULL; 1201 if (so3 == NULL) { 1202 error = ECONNREFUSED; 1203 goto bad2; 1204 } 1205 unp = sotounpcb(so); 1206 unp2 = sotounpcb(so2); 1207 unp3 = sotounpcb(so3); 1208 UNP_PCB_LOCK(unp); 1209 UNP_PCB_LOCK(unp2); 1210 UNP_PCB_LOCK(unp3); 1211 if (unp2->unp_addr != NULL) { 1212 bcopy(unp2->unp_addr, sa, unp2->unp_addr->sun_len); 1213 unp3->unp_addr = (struct sockaddr_un *) sa; 1214 sa = NULL; 1215 } 1216 /* 1217 * unp_peercred management: 1218 * 1219 * The connecter's (client's) credentials are copied from its 1220 * process structure at the time of connect() (which is now). 1221 */ 1222 cru2x(td->td_ucred, &unp3->unp_peercred); 1223 unp3->unp_flags |= UNP_HAVEPC; 1224 /* 1225 * The receiver's (server's) credentials are copied from the 1226 * unp_peercred member of socket on which the former called 1227 * listen(); uipc_listen() cached that process's credentials 1228 * at that time so we can use them now. 1229 */ 1230 KASSERT(unp2->unp_flags & UNP_HAVEPCCACHED, 1231 ("unp_connect: listener without cached peercred")); 1232 memcpy(&unp->unp_peercred, &unp2->unp_peercred, 1233 sizeof(unp->unp_peercred)); 1234 unp->unp_flags |= UNP_HAVEPC; 1235 if (unp2->unp_flags & UNP_WANTCRED) 1236 unp3->unp_flags |= UNP_WANTCRED; 1237 UNP_PCB_UNLOCK(unp3); 1238 UNP_PCB_UNLOCK(unp2); 1239 UNP_PCB_UNLOCK(unp); 1240 #ifdef MAC 1241 SOCK_LOCK(so); 1242 mac_socketpeer_set_from_socket(so, so3); 1243 mac_socketpeer_set_from_socket(so3, so); 1244 SOCK_UNLOCK(so); 1245 #endif 1246 1247 so2 = so3; 1248 } 1249 unp = sotounpcb(so); 1250 KASSERT(unp != NULL, ("unp_connect: unp == NULL")); 1251 unp2 = sotounpcb(so2); 1252 KASSERT(unp2 != NULL, ("unp_connect: unp2 == NULL")); 1253 UNP_PCB_LOCK(unp); 1254 UNP_PCB_LOCK(unp2); 1255 error = unp_connect2(so, so2, PRU_CONNECT); 1256 UNP_PCB_UNLOCK(unp2); 1257 UNP_PCB_UNLOCK(unp); 1258 bad2: 1259 UNP_GLOBAL_WUNLOCK(); 1260 if (vfslocked) 1261 /* 1262 * Giant has been previously acquired. This means filesystem 1263 * isn't MPSAFE. Do it once again. 1264 */ 1265 mtx_lock(&Giant); 1266 bad: 1267 if (vp != NULL) 1268 vput(vp); 1269 VFS_UNLOCK_GIANT(vfslocked); 1270 free(sa, M_SONAME); 1271 UNP_GLOBAL_WLOCK(); 1272 UNP_PCB_LOCK(unp); 1273 unp->unp_flags &= ~UNP_CONNECTING; 1274 UNP_PCB_UNLOCK(unp); 1275 return (error); 1276 } 1277 1278 static int 1279 unp_connect2(struct socket *so, struct socket *so2, int req) 1280 { 1281 struct unpcb *unp; 1282 struct unpcb *unp2; 1283 1284 unp = sotounpcb(so); 1285 KASSERT(unp != NULL, ("unp_connect2: unp == NULL")); 1286 unp2 = sotounpcb(so2); 1287 KASSERT(unp2 != NULL, ("unp_connect2: unp2 == NULL")); 1288 1289 UNP_GLOBAL_WLOCK_ASSERT(); 1290 UNP_PCB_LOCK_ASSERT(unp); 1291 UNP_PCB_LOCK_ASSERT(unp2); 1292 1293 if (so2->so_type != so->so_type) 1294 return (EPROTOTYPE); 1295 unp->unp_conn = unp2; 1296 1297 switch (so->so_type) { 1298 case SOCK_DGRAM: 1299 LIST_INSERT_HEAD(&unp2->unp_refs, unp, unp_reflink); 1300 soisconnected(so); 1301 break; 1302 1303 case SOCK_STREAM: 1304 unp2->unp_conn = unp; 1305 if (req == PRU_CONNECT && 1306 ((unp->unp_flags | unp2->unp_flags) & UNP_CONNWAIT)) 1307 soisconnecting(so); 1308 else 1309 soisconnected(so); 1310 soisconnected(so2); 1311 break; 1312 1313 default: 1314 panic("unp_connect2"); 1315 } 1316 return (0); 1317 } 1318 1319 static void 1320 unp_disconnect(struct unpcb *unp, struct unpcb *unp2) 1321 { 1322 struct socket *so; 1323 1324 KASSERT(unp2 != NULL, ("unp_disconnect: unp2 == NULL")); 1325 1326 UNP_GLOBAL_WLOCK_ASSERT(); 1327 UNP_PCB_LOCK_ASSERT(unp); 1328 UNP_PCB_LOCK_ASSERT(unp2); 1329 1330 unp->unp_conn = NULL; 1331 switch (unp->unp_socket->so_type) { 1332 case SOCK_DGRAM: 1333 LIST_REMOVE(unp, unp_reflink); 1334 so = unp->unp_socket; 1335 SOCK_LOCK(so); 1336 so->so_state &= ~SS_ISCONNECTED; 1337 SOCK_UNLOCK(so); 1338 break; 1339 1340 case SOCK_STREAM: 1341 soisdisconnected(unp->unp_socket); 1342 unp2->unp_conn = NULL; 1343 soisdisconnected(unp2->unp_socket); 1344 break; 1345 } 1346 } 1347 1348 /* 1349 * unp_pcblist() walks the global list of struct unpcb's to generate a 1350 * pointer list, bumping the refcount on each unpcb. It then copies them out 1351 * sequentially, validating the generation number on each to see if it has 1352 * been detached. All of this is necessary because copyout() may sleep on 1353 * disk I/O. 1354 */ 1355 static int 1356 unp_pcblist(SYSCTL_HANDLER_ARGS) 1357 { 1358 int error, i, n; 1359 int freeunp; 1360 struct unpcb *unp, **unp_list; 1361 unp_gen_t gencnt; 1362 struct xunpgen *xug; 1363 struct unp_head *head; 1364 struct xunpcb *xu; 1365 1366 head = ((intptr_t)arg1 == SOCK_DGRAM ? &unp_dhead : &unp_shead); 1367 1368 /* 1369 * The process of preparing the PCB list is too time-consuming and 1370 * resource-intensive to repeat twice on every request. 1371 */ 1372 if (req->oldptr == NULL) { 1373 n = unp_count; 1374 req->oldidx = 2 * (sizeof *xug) 1375 + (n + n/8) * sizeof(struct xunpcb); 1376 return (0); 1377 } 1378 1379 if (req->newptr != NULL) 1380 return (EPERM); 1381 1382 /* 1383 * OK, now we're committed to doing something. 1384 */ 1385 xug = malloc(sizeof(*xug), M_TEMP, M_WAITOK); 1386 UNP_GLOBAL_RLOCK(); 1387 gencnt = unp_gencnt; 1388 n = unp_count; 1389 UNP_GLOBAL_RUNLOCK(); 1390 1391 xug->xug_len = sizeof *xug; 1392 xug->xug_count = n; 1393 xug->xug_gen = gencnt; 1394 xug->xug_sogen = so_gencnt; 1395 error = SYSCTL_OUT(req, xug, sizeof *xug); 1396 if (error) { 1397 free(xug, M_TEMP); 1398 return (error); 1399 } 1400 1401 unp_list = malloc(n * sizeof *unp_list, M_TEMP, M_WAITOK); 1402 1403 UNP_GLOBAL_RLOCK(); 1404 for (unp = LIST_FIRST(head), i = 0; unp && i < n; 1405 unp = LIST_NEXT(unp, unp_link)) { 1406 UNP_PCB_LOCK(unp); 1407 if (unp->unp_gencnt <= gencnt) { 1408 if (cr_cansee(req->td->td_ucred, 1409 unp->unp_socket->so_cred)) { 1410 UNP_PCB_UNLOCK(unp); 1411 continue; 1412 } 1413 unp_list[i++] = unp; 1414 unp->unp_refcount++; 1415 } 1416 UNP_PCB_UNLOCK(unp); 1417 } 1418 UNP_GLOBAL_RUNLOCK(); 1419 n = i; /* In case we lost some during malloc. */ 1420 1421 error = 0; 1422 xu = malloc(sizeof(*xu), M_TEMP, M_WAITOK | M_ZERO); 1423 for (i = 0; i < n; i++) { 1424 unp = unp_list[i]; 1425 UNP_PCB_LOCK(unp); 1426 unp->unp_refcount--; 1427 if (unp->unp_refcount != 0 && unp->unp_gencnt <= gencnt) { 1428 xu->xu_len = sizeof *xu; 1429 xu->xu_unpp = unp; 1430 /* 1431 * XXX - need more locking here to protect against 1432 * connect/disconnect races for SMP. 1433 */ 1434 if (unp->unp_addr != NULL) 1435 bcopy(unp->unp_addr, &xu->xu_addr, 1436 unp->unp_addr->sun_len); 1437 if (unp->unp_conn != NULL && 1438 unp->unp_conn->unp_addr != NULL) 1439 bcopy(unp->unp_conn->unp_addr, 1440 &xu->xu_caddr, 1441 unp->unp_conn->unp_addr->sun_len); 1442 bcopy(unp, &xu->xu_unp, sizeof *unp); 1443 sotoxsocket(unp->unp_socket, &xu->xu_socket); 1444 UNP_PCB_UNLOCK(unp); 1445 error = SYSCTL_OUT(req, xu, sizeof *xu); 1446 } else { 1447 freeunp = (unp->unp_refcount == 0); 1448 UNP_PCB_UNLOCK(unp); 1449 if (freeunp) { 1450 UNP_PCB_LOCK_DESTROY(unp); 1451 uma_zfree(unp_zone, unp); 1452 } 1453 } 1454 } 1455 free(xu, M_TEMP); 1456 if (!error) { 1457 /* 1458 * Give the user an updated idea of our state. If the 1459 * generation differs from what we told her before, she knows 1460 * that something happened while we were processing this 1461 * request, and it might be necessary to retry. 1462 */ 1463 xug->xug_gen = unp_gencnt; 1464 xug->xug_sogen = so_gencnt; 1465 xug->xug_count = unp_count; 1466 error = SYSCTL_OUT(req, xug, sizeof *xug); 1467 } 1468 free(unp_list, M_TEMP); 1469 free(xug, M_TEMP); 1470 return (error); 1471 } 1472 1473 SYSCTL_PROC(_net_local_dgram, OID_AUTO, pcblist, CTLFLAG_RD, 1474 (caddr_t)(long)SOCK_DGRAM, 0, unp_pcblist, "S,xunpcb", 1475 "List of active local datagram sockets"); 1476 SYSCTL_PROC(_net_local_stream, OID_AUTO, pcblist, CTLFLAG_RD, 1477 (caddr_t)(long)SOCK_STREAM, 0, unp_pcblist, "S,xunpcb", 1478 "List of active local stream sockets"); 1479 1480 static void 1481 unp_shutdown(struct unpcb *unp) 1482 { 1483 struct unpcb *unp2; 1484 struct socket *so; 1485 1486 UNP_GLOBAL_WLOCK_ASSERT(); 1487 UNP_PCB_LOCK_ASSERT(unp); 1488 1489 unp2 = unp->unp_conn; 1490 if (unp->unp_socket->so_type == SOCK_STREAM && unp2 != NULL) { 1491 so = unp2->unp_socket; 1492 if (so != NULL) 1493 socantrcvmore(so); 1494 } 1495 } 1496 1497 static void 1498 unp_drop(struct unpcb *unp, int errno) 1499 { 1500 struct socket *so = unp->unp_socket; 1501 struct unpcb *unp2; 1502 1503 UNP_GLOBAL_WLOCK_ASSERT(); 1504 UNP_PCB_LOCK_ASSERT(unp); 1505 1506 so->so_error = errno; 1507 unp2 = unp->unp_conn; 1508 if (unp2 == NULL) 1509 return; 1510 1511 UNP_PCB_LOCK(unp2); 1512 unp_disconnect(unp, unp2); 1513 UNP_PCB_UNLOCK(unp2); 1514 } 1515 1516 static void 1517 unp_freerights(struct file **rp, int fdcount) 1518 { 1519 int i; 1520 struct file *fp; 1521 1522 for (i = 0; i < fdcount; i++) { 1523 /* 1524 * Zero the pointer before calling unp_discard since it may 1525 * end up in unp_gc().. 1526 * 1527 * XXXRW: This is less true than it used to be. 1528 */ 1529 fp = *rp; 1530 *rp++ = NULL; 1531 unp_discard(fp); 1532 } 1533 } 1534 1535 int 1536 unp_externalize(struct mbuf *control, struct mbuf **controlp) 1537 { 1538 struct thread *td = curthread; /* XXX */ 1539 struct cmsghdr *cm = mtod(control, struct cmsghdr *); 1540 int i; 1541 int *fdp; 1542 struct file **rp; 1543 struct file *fp; 1544 void *data; 1545 socklen_t clen = control->m_len, datalen; 1546 int error, newfds; 1547 int f; 1548 u_int newlen; 1549 1550 UNP_GLOBAL_UNLOCK_ASSERT(); 1551 1552 error = 0; 1553 if (controlp != NULL) /* controlp == NULL => free control messages */ 1554 *controlp = NULL; 1555 1556 while (cm != NULL) { 1557 if (sizeof(*cm) > clen || cm->cmsg_len > clen) { 1558 error = EINVAL; 1559 break; 1560 } 1561 1562 data = CMSG_DATA(cm); 1563 datalen = (caddr_t)cm + cm->cmsg_len - (caddr_t)data; 1564 1565 if (cm->cmsg_level == SOL_SOCKET 1566 && cm->cmsg_type == SCM_RIGHTS) { 1567 newfds = datalen / sizeof(struct file *); 1568 rp = data; 1569 1570 /* If we're not outputting the descriptors free them. */ 1571 if (error || controlp == NULL) { 1572 unp_freerights(rp, newfds); 1573 goto next; 1574 } 1575 FILEDESC_XLOCK(td->td_proc->p_fd); 1576 /* if the new FD's will not fit free them. */ 1577 if (!fdavail(td, newfds)) { 1578 FILEDESC_XUNLOCK(td->td_proc->p_fd); 1579 error = EMSGSIZE; 1580 unp_freerights(rp, newfds); 1581 goto next; 1582 } 1583 /* 1584 * Now change each pointer to an fd in the global 1585 * table to an integer that is the index to the local 1586 * fd table entry that we set up to point to the 1587 * global one we are transferring. 1588 */ 1589 newlen = newfds * sizeof(int); 1590 *controlp = sbcreatecontrol(NULL, newlen, 1591 SCM_RIGHTS, SOL_SOCKET); 1592 if (*controlp == NULL) { 1593 FILEDESC_XUNLOCK(td->td_proc->p_fd); 1594 error = E2BIG; 1595 unp_freerights(rp, newfds); 1596 goto next; 1597 } 1598 1599 fdp = (int *) 1600 CMSG_DATA(mtod(*controlp, struct cmsghdr *)); 1601 for (i = 0; i < newfds; i++) { 1602 if (fdalloc(td, 0, &f)) 1603 panic("unp_externalize fdalloc failed"); 1604 fp = *rp++; 1605 td->td_proc->p_fd->fd_ofiles[f] = fp; 1606 unp_externalize_fp(fp); 1607 *fdp++ = f; 1608 } 1609 FILEDESC_XUNLOCK(td->td_proc->p_fd); 1610 } else { 1611 /* We can just copy anything else across. */ 1612 if (error || controlp == NULL) 1613 goto next; 1614 *controlp = sbcreatecontrol(NULL, datalen, 1615 cm->cmsg_type, cm->cmsg_level); 1616 if (*controlp == NULL) { 1617 error = ENOBUFS; 1618 goto next; 1619 } 1620 bcopy(data, 1621 CMSG_DATA(mtod(*controlp, struct cmsghdr *)), 1622 datalen); 1623 } 1624 1625 controlp = &(*controlp)->m_next; 1626 1627 next: 1628 if (CMSG_SPACE(datalen) < clen) { 1629 clen -= CMSG_SPACE(datalen); 1630 cm = (struct cmsghdr *) 1631 ((caddr_t)cm + CMSG_SPACE(datalen)); 1632 } else { 1633 clen = 0; 1634 cm = NULL; 1635 } 1636 } 1637 1638 m_freem(control); 1639 1640 return (error); 1641 } 1642 1643 static void 1644 unp_zone_change(void *tag) 1645 { 1646 1647 uma_zone_set_max(unp_zone, maxsockets); 1648 } 1649 1650 void 1651 unp_init(void) 1652 { 1653 1654 unp_zone = uma_zcreate("unpcb", sizeof(struct unpcb), NULL, NULL, 1655 NULL, NULL, UMA_ALIGN_PTR, 0); 1656 if (unp_zone == NULL) 1657 panic("unp_init"); 1658 uma_zone_set_max(unp_zone, maxsockets); 1659 EVENTHANDLER_REGISTER(maxsockets_change, unp_zone_change, 1660 NULL, EVENTHANDLER_PRI_ANY); 1661 LIST_INIT(&unp_dhead); 1662 LIST_INIT(&unp_shead); 1663 TASK_INIT(&unp_gc_task, 0, unp_gc, NULL); 1664 UNP_GLOBAL_LOCK_INIT(); 1665 } 1666 1667 static int 1668 unp_internalize(struct mbuf **controlp, struct thread *td) 1669 { 1670 struct mbuf *control = *controlp; 1671 struct proc *p = td->td_proc; 1672 struct filedesc *fdescp = p->p_fd; 1673 struct cmsghdr *cm = mtod(control, struct cmsghdr *); 1674 struct cmsgcred *cmcred; 1675 struct file **rp; 1676 struct file *fp; 1677 struct timeval *tv; 1678 int i, fd, *fdp; 1679 void *data; 1680 socklen_t clen = control->m_len, datalen; 1681 int error, oldfds; 1682 u_int newlen; 1683 1684 UNP_GLOBAL_UNLOCK_ASSERT(); 1685 1686 error = 0; 1687 *controlp = NULL; 1688 1689 while (cm != NULL) { 1690 if (sizeof(*cm) > clen || cm->cmsg_level != SOL_SOCKET 1691 || cm->cmsg_len > clen) { 1692 error = EINVAL; 1693 goto out; 1694 } 1695 1696 data = CMSG_DATA(cm); 1697 datalen = (caddr_t)cm + cm->cmsg_len - (caddr_t)data; 1698 1699 switch (cm->cmsg_type) { 1700 /* 1701 * Fill in credential information. 1702 */ 1703 case SCM_CREDS: 1704 *controlp = sbcreatecontrol(NULL, sizeof(*cmcred), 1705 SCM_CREDS, SOL_SOCKET); 1706 if (*controlp == NULL) { 1707 error = ENOBUFS; 1708 goto out; 1709 } 1710 1711 cmcred = (struct cmsgcred *) 1712 CMSG_DATA(mtod(*controlp, struct cmsghdr *)); 1713 cmcred->cmcred_pid = p->p_pid; 1714 cmcred->cmcred_uid = td->td_ucred->cr_ruid; 1715 cmcred->cmcred_gid = td->td_ucred->cr_rgid; 1716 cmcred->cmcred_euid = td->td_ucred->cr_uid; 1717 cmcred->cmcred_ngroups = MIN(td->td_ucred->cr_ngroups, 1718 CMGROUP_MAX); 1719 for (i = 0; i < cmcred->cmcred_ngroups; i++) 1720 cmcred->cmcred_groups[i] = 1721 td->td_ucred->cr_groups[i]; 1722 break; 1723 1724 case SCM_RIGHTS: 1725 oldfds = datalen / sizeof (int); 1726 /* 1727 * Check that all the FDs passed in refer to legal 1728 * files. If not, reject the entire operation. 1729 */ 1730 fdp = data; 1731 FILEDESC_SLOCK(fdescp); 1732 for (i = 0; i < oldfds; i++) { 1733 fd = *fdp++; 1734 if ((unsigned)fd >= fdescp->fd_nfiles || 1735 fdescp->fd_ofiles[fd] == NULL) { 1736 FILEDESC_SUNLOCK(fdescp); 1737 error = EBADF; 1738 goto out; 1739 } 1740 fp = fdescp->fd_ofiles[fd]; 1741 if (!(fp->f_ops->fo_flags & DFLAG_PASSABLE)) { 1742 FILEDESC_SUNLOCK(fdescp); 1743 error = EOPNOTSUPP; 1744 goto out; 1745 } 1746 1747 } 1748 1749 /* 1750 * Now replace the integer FDs with pointers to 1751 * the associated global file table entry.. 1752 */ 1753 newlen = oldfds * sizeof(struct file *); 1754 *controlp = sbcreatecontrol(NULL, newlen, 1755 SCM_RIGHTS, SOL_SOCKET); 1756 if (*controlp == NULL) { 1757 FILEDESC_SUNLOCK(fdescp); 1758 error = E2BIG; 1759 goto out; 1760 } 1761 1762 fdp = data; 1763 rp = (struct file **) 1764 CMSG_DATA(mtod(*controlp, struct cmsghdr *)); 1765 for (i = 0; i < oldfds; i++) { 1766 fp = fdescp->fd_ofiles[*fdp++]; 1767 *rp++ = fp; 1768 unp_internalize_fp(fp); 1769 } 1770 FILEDESC_SUNLOCK(fdescp); 1771 break; 1772 1773 case SCM_TIMESTAMP: 1774 *controlp = sbcreatecontrol(NULL, sizeof(*tv), 1775 SCM_TIMESTAMP, SOL_SOCKET); 1776 if (*controlp == NULL) { 1777 error = ENOBUFS; 1778 goto out; 1779 } 1780 tv = (struct timeval *) 1781 CMSG_DATA(mtod(*controlp, struct cmsghdr *)); 1782 microtime(tv); 1783 break; 1784 1785 default: 1786 error = EINVAL; 1787 goto out; 1788 } 1789 1790 controlp = &(*controlp)->m_next; 1791 1792 if (CMSG_SPACE(datalen) < clen) { 1793 clen -= CMSG_SPACE(datalen); 1794 cm = (struct cmsghdr *) 1795 ((caddr_t)cm + CMSG_SPACE(datalen)); 1796 } else { 1797 clen = 0; 1798 cm = NULL; 1799 } 1800 } 1801 1802 out: 1803 m_freem(control); 1804 1805 return (error); 1806 } 1807 1808 static struct mbuf * 1809 unp_addsockcred(struct thread *td, struct mbuf *control) 1810 { 1811 struct mbuf *m, *n, *n_prev; 1812 struct sockcred *sc; 1813 const struct cmsghdr *cm; 1814 int ngroups; 1815 int i; 1816 1817 ngroups = MIN(td->td_ucred->cr_ngroups, CMGROUP_MAX); 1818 1819 m = sbcreatecontrol(NULL, SOCKCREDSIZE(ngroups), SCM_CREDS, SOL_SOCKET); 1820 if (m == NULL) 1821 return (control); 1822 1823 sc = (struct sockcred *) CMSG_DATA(mtod(m, struct cmsghdr *)); 1824 sc->sc_uid = td->td_ucred->cr_ruid; 1825 sc->sc_euid = td->td_ucred->cr_uid; 1826 sc->sc_gid = td->td_ucred->cr_rgid; 1827 sc->sc_egid = td->td_ucred->cr_gid; 1828 sc->sc_ngroups = ngroups; 1829 for (i = 0; i < sc->sc_ngroups; i++) 1830 sc->sc_groups[i] = td->td_ucred->cr_groups[i]; 1831 1832 /* 1833 * Unlink SCM_CREDS control messages (struct cmsgcred), since just 1834 * created SCM_CREDS control message (struct sockcred) has another 1835 * format. 1836 */ 1837 if (control != NULL) 1838 for (n = control, n_prev = NULL; n != NULL;) { 1839 cm = mtod(n, struct cmsghdr *); 1840 if (cm->cmsg_level == SOL_SOCKET && 1841 cm->cmsg_type == SCM_CREDS) { 1842 if (n_prev == NULL) 1843 control = n->m_next; 1844 else 1845 n_prev->m_next = n->m_next; 1846 n = m_free(n); 1847 } else { 1848 n_prev = n; 1849 n = n->m_next; 1850 } 1851 } 1852 1853 /* Prepend it to the head. */ 1854 m->m_next = control; 1855 1856 return (m); 1857 } 1858 1859 static struct unpcb * 1860 fptounp(struct file *fp) 1861 { 1862 struct socket *so; 1863 1864 if (fp->f_type != DTYPE_SOCKET) 1865 return (NULL); 1866 if ((so = fp->f_data) == NULL) 1867 return (NULL); 1868 if (so->so_proto->pr_domain != &localdomain) 1869 return (NULL); 1870 return sotounpcb(so); 1871 } 1872 1873 static void 1874 unp_discard(struct file *fp) 1875 { 1876 1877 unp_externalize_fp(fp); 1878 (void) closef(fp, (struct thread *)NULL); 1879 } 1880 1881 static void 1882 unp_internalize_fp(struct file *fp) 1883 { 1884 struct unpcb *unp; 1885 1886 UNP_GLOBAL_WLOCK(); 1887 if ((unp = fptounp(fp)) != NULL) { 1888 unp->unp_file = fp; 1889 unp->unp_msgcount++; 1890 } 1891 fhold(fp); 1892 unp_rights++; 1893 UNP_GLOBAL_WUNLOCK(); 1894 } 1895 1896 static void 1897 unp_externalize_fp(struct file *fp) 1898 { 1899 struct unpcb *unp; 1900 1901 UNP_GLOBAL_WLOCK(); 1902 if ((unp = fptounp(fp)) != NULL) 1903 unp->unp_msgcount--; 1904 unp_rights--; 1905 UNP_GLOBAL_WUNLOCK(); 1906 } 1907 1908 /* 1909 * unp_defer indicates whether additional work has been defered for a future 1910 * pass through unp_gc(). It is thread local and does not require explicit 1911 * synchronization. 1912 */ 1913 static int unp_marked; 1914 static int unp_unreachable; 1915 1916 static void 1917 unp_accessable(struct file *fp) 1918 { 1919 struct unpcb *unp; 1920 1921 if ((unp = fptounp(fp)) == NULL) 1922 return; 1923 if (unp->unp_gcflag & UNPGC_REF) 1924 return; 1925 unp->unp_gcflag &= ~UNPGC_DEAD; 1926 unp->unp_gcflag |= UNPGC_REF; 1927 unp_marked++; 1928 } 1929 1930 static void 1931 unp_gc_process(struct unpcb *unp) 1932 { 1933 struct socket *soa; 1934 struct socket *so; 1935 struct file *fp; 1936 1937 /* Already processed. */ 1938 if (unp->unp_gcflag & UNPGC_SCANNED) 1939 return; 1940 fp = unp->unp_file; 1941 /* 1942 * Check for a socket potentially in a cycle. It must be in a 1943 * queue as indicated by msgcount, and this must equal the file 1944 * reference count. Note that when msgcount is 0 the file is NULL. 1945 */ 1946 if ((unp->unp_gcflag & UNPGC_REF) == 0 && fp && 1947 unp->unp_msgcount != 0 && fp->f_count == unp->unp_msgcount) { 1948 unp->unp_gcflag |= UNPGC_DEAD; 1949 unp_unreachable++; 1950 return; 1951 } 1952 /* 1953 * Mark all sockets we reference with RIGHTS. 1954 */ 1955 so = unp->unp_socket; 1956 SOCKBUF_LOCK(&so->so_rcv); 1957 unp_scan(so->so_rcv.sb_mb, unp_accessable); 1958 SOCKBUF_UNLOCK(&so->so_rcv); 1959 /* 1960 * Mark all sockets in our accept queue. 1961 */ 1962 ACCEPT_LOCK(); 1963 TAILQ_FOREACH(soa, &so->so_comp, so_list) { 1964 SOCKBUF_LOCK(&soa->so_rcv); 1965 unp_scan(soa->so_rcv.sb_mb, unp_accessable); 1966 SOCKBUF_UNLOCK(&soa->so_rcv); 1967 } 1968 ACCEPT_UNLOCK(); 1969 unp->unp_gcflag |= UNPGC_SCANNED; 1970 } 1971 1972 static int unp_recycled; 1973 SYSCTL_INT(_net_local, OID_AUTO, recycled, CTLFLAG_RD, &unp_recycled, 0, 1974 "Number of unreachable sockets claimed by the garbage collector."); 1975 1976 static int unp_taskcount; 1977 SYSCTL_INT(_net_local, OID_AUTO, taskcount, CTLFLAG_RD, &unp_taskcount, 0, 1978 "Number of times the garbage collector has run."); 1979 1980 static void 1981 unp_gc(__unused void *arg, int pending) 1982 { 1983 struct unp_head *heads[] = { &unp_dhead, &unp_shead, NULL }; 1984 struct unp_head **head; 1985 struct file **unref; 1986 struct unpcb *unp; 1987 int i; 1988 1989 unp_taskcount++; 1990 UNP_GLOBAL_RLOCK(); 1991 /* 1992 * First clear all gc flags from previous runs. 1993 */ 1994 for (head = heads; *head != NULL; head++) 1995 LIST_FOREACH(unp, *head, unp_link) 1996 unp->unp_gcflag = 0; 1997 /* 1998 * Scan marking all reachable sockets with UNPGC_REF. Once a socket 1999 * is reachable all of the sockets it references are reachable. 2000 * Stop the scan once we do a complete loop without discovering 2001 * a new reachable socket. 2002 */ 2003 do { 2004 unp_unreachable = 0; 2005 unp_marked = 0; 2006 for (head = heads; *head != NULL; head++) 2007 LIST_FOREACH(unp, *head, unp_link) 2008 unp_gc_process(unp); 2009 } while (unp_marked); 2010 UNP_GLOBAL_RUNLOCK(); 2011 if (unp_unreachable == 0) 2012 return; 2013 /* 2014 * Allocate space for a local list of dead unpcbs. 2015 */ 2016 unref = malloc(unp_unreachable * sizeof(struct file *), 2017 M_TEMP, M_WAITOK); 2018 /* 2019 * Iterate looking for sockets which have been specifically marked 2020 * as as unreachable and store them locally. 2021 */ 2022 UNP_GLOBAL_RLOCK(); 2023 for (i = 0, head = heads; *head != NULL; head++) 2024 LIST_FOREACH(unp, *head, unp_link) 2025 if (unp->unp_gcflag & UNPGC_DEAD) { 2026 unref[i++] = unp->unp_file; 2027 fhold(unp->unp_file); 2028 KASSERT(unp->unp_file != NULL, 2029 ("unp_gc: Invalid unpcb.")); 2030 KASSERT(i <= unp_unreachable, 2031 ("unp_gc: incorrect unreachable count.")); 2032 } 2033 UNP_GLOBAL_RUNLOCK(); 2034 /* 2035 * Now flush all sockets, free'ing rights. This will free the 2036 * struct files associated with these sockets but leave each socket 2037 * with one remaining ref. 2038 */ 2039 for (i = 0; i < unp_unreachable; i++) 2040 sorflush(unref[i]->f_data); 2041 /* 2042 * And finally release the sockets so they can be reclaimed. 2043 */ 2044 for (i = 0; i < unp_unreachable; i++) 2045 fdrop(unref[i], NULL); 2046 unp_recycled += unp_unreachable; 2047 free(unref, M_TEMP); 2048 } 2049 2050 void 2051 unp_dispose(struct mbuf *m) 2052 { 2053 2054 if (m) 2055 unp_scan(m, unp_discard); 2056 } 2057 2058 static void 2059 unp_scan(struct mbuf *m0, void (*op)(struct file *)) 2060 { 2061 struct mbuf *m; 2062 struct file **rp; 2063 struct cmsghdr *cm; 2064 void *data; 2065 int i; 2066 socklen_t clen, datalen; 2067 int qfds; 2068 2069 while (m0 != NULL) { 2070 for (m = m0; m; m = m->m_next) { 2071 if (m->m_type != MT_CONTROL) 2072 continue; 2073 2074 cm = mtod(m, struct cmsghdr *); 2075 clen = m->m_len; 2076 2077 while (cm != NULL) { 2078 if (sizeof(*cm) > clen || cm->cmsg_len > clen) 2079 break; 2080 2081 data = CMSG_DATA(cm); 2082 datalen = (caddr_t)cm + cm->cmsg_len 2083 - (caddr_t)data; 2084 2085 if (cm->cmsg_level == SOL_SOCKET && 2086 cm->cmsg_type == SCM_RIGHTS) { 2087 qfds = datalen / sizeof (struct file *); 2088 rp = data; 2089 for (i = 0; i < qfds; i++) 2090 (*op)(*rp++); 2091 } 2092 2093 if (CMSG_SPACE(datalen) < clen) { 2094 clen -= CMSG_SPACE(datalen); 2095 cm = (struct cmsghdr *) 2096 ((caddr_t)cm + CMSG_SPACE(datalen)); 2097 } else { 2098 clen = 0; 2099 cm = NULL; 2100 } 2101 } 2102 } 2103 m0 = m0->m_act; 2104 } 2105 } 2106 2107 #ifdef DDB 2108 static void 2109 db_print_indent(int indent) 2110 { 2111 int i; 2112 2113 for (i = 0; i < indent; i++) 2114 db_printf(" "); 2115 } 2116 2117 static void 2118 db_print_unpflags(int unp_flags) 2119 { 2120 int comma; 2121 2122 comma = 0; 2123 if (unp_flags & UNP_HAVEPC) { 2124 db_printf("%sUNP_HAVEPC", comma ? ", " : ""); 2125 comma = 1; 2126 } 2127 if (unp_flags & UNP_HAVEPCCACHED) { 2128 db_printf("%sUNP_HAVEPCCACHED", comma ? ", " : ""); 2129 comma = 1; 2130 } 2131 if (unp_flags & UNP_WANTCRED) { 2132 db_printf("%sUNP_WANTCRED", comma ? ", " : ""); 2133 comma = 1; 2134 } 2135 if (unp_flags & UNP_CONNWAIT) { 2136 db_printf("%sUNP_CONNWAIT", comma ? ", " : ""); 2137 comma = 1; 2138 } 2139 if (unp_flags & UNP_CONNECTING) { 2140 db_printf("%sUNP_CONNECTING", comma ? ", " : ""); 2141 comma = 1; 2142 } 2143 if (unp_flags & UNP_BINDING) { 2144 db_printf("%sUNP_BINDING", comma ? ", " : ""); 2145 comma = 1; 2146 } 2147 } 2148 2149 static void 2150 db_print_xucred(int indent, struct xucred *xu) 2151 { 2152 int comma, i; 2153 2154 db_print_indent(indent); 2155 db_printf("cr_version: %u cr_uid: %u cr_ngroups: %d\n", 2156 xu->cr_version, xu->cr_uid, xu->cr_ngroups); 2157 db_print_indent(indent); 2158 db_printf("cr_groups: "); 2159 comma = 0; 2160 for (i = 0; i < xu->cr_ngroups; i++) { 2161 db_printf("%s%u", comma ? ", " : "", xu->cr_groups[i]); 2162 comma = 1; 2163 } 2164 db_printf("\n"); 2165 } 2166 2167 static void 2168 db_print_unprefs(int indent, struct unp_head *uh) 2169 { 2170 struct unpcb *unp; 2171 int counter; 2172 2173 counter = 0; 2174 LIST_FOREACH(unp, uh, unp_reflink) { 2175 if (counter % 4 == 0) 2176 db_print_indent(indent); 2177 db_printf("%p ", unp); 2178 if (counter % 4 == 3) 2179 db_printf("\n"); 2180 counter++; 2181 } 2182 if (counter != 0 && counter % 4 != 0) 2183 db_printf("\n"); 2184 } 2185 2186 DB_SHOW_COMMAND(unpcb, db_show_unpcb) 2187 { 2188 struct unpcb *unp; 2189 2190 if (!have_addr) { 2191 db_printf("usage: show unpcb <addr>\n"); 2192 return; 2193 } 2194 unp = (struct unpcb *)addr; 2195 2196 db_printf("unp_socket: %p unp_vnode: %p\n", unp->unp_socket, 2197 unp->unp_vnode); 2198 2199 db_printf("unp_ino: %d unp_conn: %p\n", unp->unp_ino, 2200 unp->unp_conn); 2201 2202 db_printf("unp_refs:\n"); 2203 db_print_unprefs(2, &unp->unp_refs); 2204 2205 /* XXXRW: Would be nice to print the full address, if any. */ 2206 db_printf("unp_addr: %p\n", unp->unp_addr); 2207 2208 db_printf("unp_cc: %d unp_mbcnt: %d unp_gencnt: %llu\n", 2209 unp->unp_cc, unp->unp_mbcnt, 2210 (unsigned long long)unp->unp_gencnt); 2211 2212 db_printf("unp_flags: %x (", unp->unp_flags); 2213 db_print_unpflags(unp->unp_flags); 2214 db_printf(")\n"); 2215 2216 db_printf("unp_peercred:\n"); 2217 db_print_xucred(2, &unp->unp_peercred); 2218 2219 db_printf("unp_refcount: %u\n", unp->unp_refcount); 2220 } 2221 #endif 2222